Fabric slitting method and apparatus for circular knitting machine

ABSTRACT

Selected transfer bits or jacks pick up and hold the yarn at each knitting station while it is knit on needles positioned adjacent sides of the held loops. The loops held on the transfer jacks then move into engagement with a cutting device to sever the yarn and thereby slit the fabric in a walewise direction as it is being knit on a circular knitting machine. The cutting device is disclosed as either a heated wire or a mechanical cutter.

ilnite States Patent [191 Fregeolle FABRIC SLITTING METHOD AND APPARATUSFOR CIRCULAR KNITTING MAQNE [75] Inventor: Oscar Fregeolle, Hickory, NC.

[73] Assignee: Pilot Research Corporation,

Valdese, NC.

[22] Filed: June 12, 1969 [21] Appl. No.: 832,795

[52] US. Cl. 66/147, 66/177 [51] Int. Cl D04b 33/00 [58] Field of Search66/175, 176, 177, 140,

[56] References Cited UNITED STATES PATENTS 8/1961 Payne et al. 66/1478/1961 Payne et al. 66/147 [111 3,834,191 [4 1 Sept. 10, 1974 3,564,8732/1971 Beane 66/177 R27,886 l/l974 Johnson 66/177 FOREIGN PATENTS ORAPPLICATIONS 1,302,224 7/1962 France 66/92 Primary Examiner-RonaldFeldbaum Attorney, Agent, or Firm-Parrott, Bell, Seltzer, Park andGibson [5 7] ABSTRACT Selected transfer bits or jacks pick up and holdthe yarn at each knitting station while it is knit on needles positionedadjacent sides of the held loops. The loops held on the transfer jacksthen move into engagement with a cutting device to sever the yarn andthereby slit the fabric in a walewise direction as it is being knit on acircular knitting machine. The cutting device is disclosed as either aheated wire or a mechanical cutter.

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SNEEI 3 N 3 VIIIIIIIIIIIIIIII 1m I t INVENTOR: OSCAR FR E EOLLEATTORNEYS FABRIC SLITTING METHOD AND APPARATUS FDR CIRCULAR KNITTINGMACHINE This invention relates generally to circular knitting machinesand more particularly to an apparatus and method for slitting seamlesstubular fabric in a walewise direction as it is being knit on a hosieryknitting machine. The invention is of particular value in slittingseamless blanks to be used in forming panty hose but may also be used toslit other types of blanks, such as leotards and the like.

Panty hose type garments are usually formed by knitting elongatedseamless hosiety blankson a circular hosiery knitting machine and thenslitting the blanks from the upper edge downwardly a predetermineddistance. A pair of adjacent blanks are then connected together bysewing together the corresponding slit edges of the pair of blanks toform the body portion of the panty hose. The slitting of the stockingblank is usually carried out during an operation which is separate fromthe knitting operation. It has recently been proposed to slit thehosiery blanks as they are being knit by mounting a hooked element forradial movement on the dial. This hooked element picks up loops of yarnat each knitting station and the held loops are cut to slit the fabricas it is being knit. However, the usual transfer jacks cannot be usedwith this hooked element on the dial so that an inturned welt may not beformed on the hosiery blank.

With the foregoing in mind, it is an object of the present invention toprovide a method and apparatus for slitting seamless hosiery blanks on acircular knitting machine whereby selected transfer jacks operate tohold yarn loops and position them to be cut after the yarn is knit atadjacent sides of the held loop. Since selected transfer jacks are usedto hold the yarn loops, the remaining transfer jacks may be operated inthe usual manner to form an inturned welt on the hosiery blanks.

One embodiment of the held loop cutting device includes a heated wiresupported closely adjacent the outside of the needle circle and cammeans for imparting an outward movement to thetransfer jacks which holdthe loop of yarn so that the held yarn loop engages the heated wire andis severed.

Another embodiment of the held loop cutting device includes a mechanicalcutter having a movable blade element which is supported to reciprocateabove the circle of needles and timed to engage and cut the loop held bythe transfer jack after the yarn has been knit at adjacent sides of theheld loop. The mechanical cutter is operative from cam means on theknitting machine which is timed to move the movable blade elementinwardly at the time that the held loop passes thereby. The blocksupporting the reciprocating blade extends inwardly into close proximityto the needle cylinder and is provided with cam surfaces on oppositesides to serve as a latch opener.

Some of the objects of the invention having been stated, other objectswill appear as the-description proceeds when taken in connection withthe accompanying drawings, in which FIG. 1 is an isometric view of atypical seamless panty hose blank, illustrating the manner in which aslit is formed therein by means of the present invention;

FIG. 2 is a horizontal section plan view through the operating camswhich control the radial movement of the transfer jacks, lookingdownwardly on the needle circle;

FIG. 3 is a fragmentary isometric view of a portion of the dial bed ofthe knitting machine and illustrating the manner in which selectedtransfer jacks are projected outwardly to pick up and hold loops of yarnfrom each knitting station;

FIG. 4 is a fragmentary view of a portion of the needle circle.illustrating the manner in which the selected transfer jacks areprojected outwardly above three inactive needles to pick up and hold ayarn loop at the main knitting station;

FIG. 5 is a view similar to FIG. 4'but showing the manner in which theloop of yarn is held on the transfer jacks after the active needles onopposite sides thereof have knit;

FIG. 6 is a view similar to FIG. 4 but illustrating the manner in whichthe transfer jacks pick up the yarn at the second or auxiliary yarnfeeding station and wherein the same three needles remain in a loweredor inactive position at this knitting station;

FIG. 7 is another fragmentary view of the needle circle, illustratingthe manner in which the held yarn loops, formed at each knittingstation, are projected outwardly by the transfer jacks to be engaged bya heated wire and severed;

FIG. 8 is a fragmentary vertical sectional view through the upper end ofthe needle cylinder and the outer portion of the dial, illustrating themanner in which the heated wire is supported to engage the, held yarnloops and sever the same;

FIG. 9 is an isometric view of the sinker cap of the machine andillustrating a mechanical cutter supported thereon and the manner inwhich the cutter is operated by means of a rotating cam on the knittingmachine;

FIG. 10 is a fragmentary plan view of the mechanical cutter illustratingthe manner in which the inner end of the movable blade element movesoutwardly above the circle of needles to receive the held yarn loop; and

FIG. 1 l is a vertical sectional view taken substantially along the line1l-1l in FIG. 9 and illustrating the upper portion of the needlecylinder and the dial in section with the held loop in position to becut by the movable blade element.

The slitting apparatus and method of the present invention may beutilized on circular hosiery knitting machines having any number offeeding and knitting stations. In the drawings, the slitting apparatusis illustrated in operation with a circular knitting machine havingspaced apart first and second or main and auxiliary feeding and knittingstations. While the slitting apparatus and method of the presentinvention may be used in slitting many different types of seamlesstubular fabric in a walewise direction as it is being knit, it is ofparticular value in the knitting of panty hose blanks,

such as indicated at B in FIG. 1.

The blank B is usually knit from top to bottom and may be knit as astraight tube or it may be tapered by gradually reducing the length orsize of the stitches as knitting of the tube continues, in the wellknown manner. The blank B preferably includes a small inturned welt 10at the upper end thereof and'an integrally formed shadow welt 10a ofsingle ply material. A body portion 11 extends downwardly from theshadow weltl0a. The body portion 11 is preferably knit of a fairly heavyyarn and may either be plain knit or may utilize a pattern of tuckand/or held stitches to form a desired pattern therein. A band of runresilient fabric 12 is nier yarn and may be either plain knit or containa pattern of special stitches, if desired. The lower end of the leg 13is provided with a reinforced toe portion 14 which may be closed in anysuitable manner, as by seaming or looping. If desired, the blank B maybe provided with reciprocatorally knit heel and/or toe pockets formedtherein in the conventional manner. While the welt 10,-shadow welt a,and the body portion 11 are being knit, the slitting apparatus of thepresent invention is operated to form a walewise extending slitextending from the upper end of the blank B and down to the non-run band12 to form opposed free cut edges 15, 15a.

Each embodiment of the slitting apparatus of the present invention isillustrated as being associated with a Scott & Williams type two-feedhosiery .knitting machine, however, it is to be understood that thisapparatus mayalso be used with other types of circular hosiery knittingmachines. Only those portions of the knitting machine have beenillustrated and described which are necessary to an understanding of thepresent invention.

Referring to the first embodiment, shown in FIGS. 2-8, the machineincludes a circle of latch needles N which are supported for verticalmovement in a rotating needle cylinder 19 (FIG. 8) and a first or mainyarn feeding station 20is provided in a latch ring 21 which surroundsthe needle circle N. A second or auxiliary yarn feeding station 22 isspaced from the first feeding station 20 and each yarn feeding stationis positioned above respective knitting stations having the usualknitting cams, not shown. The yarn feeding stations 20, 22 are providedwith respective yarn feed fingers 24, 25 which are supported formovement into and out of yarn feeding position, in a conventionalmanner. I

The usual needle selecting means, not shown, is provided in advance ofeach knitting station for cooperating with selector jacks positionedbeneath the needles so that the needles may pass the knitting station ata knit level, a tuck level, or a float or welt level. The fingers 24, 25feed respective yarns Y and Y to the needles, in the usual manner.

As shown in FIG. 3, a dial bed is supported inside of the circle ofneedles N and on the lower end of a drive shaft 31 (FIG. 2) which isconnected in the usual manner to the needle cylinder drive mechanism,not shown, so that the dial bed 30 rotates in timed relationship withthe circle of needles N. Radial grooves are formed in the dial bed 30and slidably support conventional two-part transfer bits or jacks,broadly indicated at T (FIG. 3). In accordance with the presentinvention, a pair of special two-part transfer jacks, indicated at T inFIG. 3, are supportedin the dial bed 30 in alignment with the positionin the needIe circle where the slit is to be formed in the tubularfabric.

Each of the transfer jacks T and T is preferably formed in aconventional manner of two juxtaposed mating parts with the innerportions being identical and the outer portions being curved or bowedoutwardly from each other to form a needle receiving opening 31, andeach transfer jack is provided with a hooked outer end portion 32. Asshown in FIG. 3, the special transfer jacks T each have upstandingoperating butts 33 which are higher than the operating butts of theregular transfer jacks T, for purposes to be presently described.

The radial position of the transfer jacks is determined by suitable cammeans supported above the dial bed 30 and adapted to engage theupstanding operating butts (FIG. 2). The cam means includes a fixedouter cam ring 36, a fixed inner cam ring 37, and vertically movablecams 40, 41, 42 and 43. The cams 40, 43, shown in dotted lines, are theconventional transfer cams of the machine and their operation will bepresently described.

As shown in FIG. 8, a sinker bed 45 is suitably sup ported on the upperend of the needle cylinder 19 and supports conventional sinkers 46 forradial movement between the needles N in a conventional manner. A sinkercap 47 is supported on the sinker bed 45 and contains the usual cams,not shown, for radially positioning the sinkers 46. Yarn severing meansin the form of a high resistance electric heater wire 50 is supported atits upper end on a bracket 51 (FIG. 8) carried by the latch ring 21. Thebracket 51 is preferably supported in a keyway in the latch ring 21 sothat the location of the lower inner end of the heater wire 50 may beadjusted, relative to the needles N.

The lower inner end of the heater wire 50 is preferably bent to form aninner pointed end (FIGS. .2 and 3) which is positioned closely adjacentthe circle of needles N and beneath the level of the transfer jacks T sothat when the transfer jacks are projected outwardly, in a manner to bepresently described, the yarn loops held thereby are pushed outwardly atan angle from the upper ends of the needles N to a position where theywill contact the heated wire 50 and to be severed thereby. The upperends of the wire 50 are suitably connected by electrical wires 52, 52ato a suitable source of electrical energy, not shown, by means of apattern controlled switch 53 (FIG. 8) so that the wire 50 is heated onlyduring the time that the slitting operation takes place. The switch 53may be operated from any suitable pattern device on the machine, such asthe pattern chain, not shown.

METHOD OF OPERATION As is well known, fine gauge sheer panty hose blanksare usually knit on circular hosiery knitting machines having 400 ormore needles in the needle cylinder and the blanks are usually knit ofnylon yarn or other suitable types of thermoplastic yarn which may beeasily severed by subjecting the same to intense heat, such as a heatedwire. The knitting of the particular type of panty hose blank B shown inFIG. 1 will now be described, it being understood that other types ofpanty hose blanks may also be knit in accordance with the presentinvention while forming a walewise extending slit in predeterminedportions thereof.

To begin knitting at the upper end of the blank B with the formation ofan intumed welt, the make-up is formed at the main yarn feeding station20 where alternate needles are raised to pick up the yarn Y from thefeed finger 24 while intervening needles, as well as three consecutiveinactive needles indicated at N in FIG. 4, remain at a welt or non-yarntaking level.

The special transfer jacks T are moved outwardly by the cam 41 (FIG. 2)engaging their butts so that the outer hooked ends pick up and holdloops of yarn thereon. As is well known, the transfer jacks are alignedwith every other needle and the special transfer jacks T are alignedwith the first and last of the inactive needles N while the centerinactive needle is positioned between the special transfer jacks.

During the second course, all of the needles are raised to activeposition to pick up and knit the yarn Y, except the three inactiveneedles N which remain at a welt level and do not take yarn. A secondloop of the yarn Y is thus held on the special transfer jacks T whilethe active needles at each side knit the yarn. During the third course,the cam 41 moves down to fully operative position so all jacks T and Tmove out to pick up transfer loops of yarn at the main feed 20 whilealternate needles remain in a low position.

Duringthe next rotation of the needle cylinder 19, the cam 41 is raisedfar enough to engage only the high butts of the special transfer jacks Tso that their outer ends move out over the three lowered inactiveneedles N to pick up and hold loops of yarn thereon. All needles thenknit at the auxiliary yarn feeding station 22, except the three needlesN which remain in a low inactive position and a loop of yarn Y is pickedup and held on the special transfer jacks T. The cam 42 is lowered farenough to engage only the high butts of the special transfer jacks T sothat they move outwardly to cause the held loops of yarn to engage theheated wire 50 and be severed thereby. During the knitting of theremaining courses of the inturned welt 10, the special transfer jacks Tare projected outwardly to pick up and hold yarn loops at the main andauxiliary feed stations 20, 22 and the held loops are severed by theheated wire 50. The loops of the transfer course which are being held onthe regular transfer jacks T extend downwardly from the dial 30 and donot engage the heated wire 50, as shown in dotted lines in FIG. 8.

After the desired length of fabric is knit to form the inturned welt 10,the transfer cam 40 (FIG. 2) is lowered to project the regular transferpoints T outwardly while alternate needles are raised to pass upwardlythrough the needle opening 31. As the transfer jacks T are drawninwardly by the cam 43, the stitch loops held thereon are transferred tothe cylinder needles N to complete the transfer as all needles pick upyarn Y and knit at the main station 20, except the three needles N whichremain in a lower inactive position.

As knitting of the single ply shadow welt a and body portion 11continues, all needles knit at each knitting station, except the threeinactive needles N which remain in a lower inactive position at eachstation, as illustrated in FIGS. 4 and 6. At the same time, thecorresponding special transfer jacks T pick up and hold yarn loops ofthe yarn Y and Y at each station and carry it to the heated wire 50where the yarn loops are severed. To cease the slitting operation, thecam 41 is raised so that the special transfer jacks T are not projectedout at the knitting stations. To start knitting on the three inactiveneedles N at the lower end of the slit, the endmost inactive needles arefirst raised to take and knit yarn at one or more stations and then themiddle inactive needle is raised to take yarn and knit at each station.The switch 53 also operates to stop the flow of electricity to theheater wire 50.

Seamless knitting on all needles then continues through the band 12 ofrun resilient stitches, the leg portion 13 and the toe portion 14 withall needles knitting at each station and any suitable type of yarn andstitches maybe formed therein. When the panty hose blank is removedfrom'the knitting machine, the slit is properly formed in the properposition and is of the desired length. The panty hose blank B is thenready to be joined to another panty hose blank, in the usual manner, tocomplete the panty hose garment.

SECOND EMBODIMENT A second embodiment of yarn severing means isillustrated in FIGS. 9-11 which does not require a heater wire, asillustrated in the first embodiment shown in FIGS. 2-8. The embodimentof yarn severing means shown in FIGS. 9-11 includes a mechanical cutterwhich is operated in timed relationship to rotation of the circle ofneedles for cutting the held loops of yarn as they pass the mechanicalcutter. This mechanical cutter is illustrated as being applied to thesame type of machine as the heated wire cutter shown in FIGS. 2-8 andlike reference characters are applied to corresponding parts of theknitting machine shown in FIGS. 9-11. The machine is provided with theusual vertical drive shaft 55 (FIG. 9) which is drivingly connected, ina well-known manner, to the drive shaft 31 of the dial bed 30.

The mechanical cutter includes a support block 56 which is fixed on theupper surface of the sinker cap 47 by screws 57. The inner portion ofthe support block 56 extends inwardly beyond the inner portion of thesinker cap 47 (FIG. 10) and opposite end portions thereof are tapered toform latch opening cam surfaces 60.

A movable blade element 61 is supported for sliding movement in atransverse groove in the support block 56 for inward and outwardreciprocation. When the movable blade 61 is in its innermost position(FIG. 10), a V-shaped cutting slot 62 is positioned to receive theoutwardly inclined loop of yarn which is held by the special transferjack T (FIG. 11), as the held loop is brought around by the needles Nand the transfer jack into the slot 62. The inner end of the blade 61 ispositioned closely adjacent the circle of needles so that it does notengage any inwardly inclined loops which are held by the other transferjacks T (shown in dotted lines in FIG. 11).

A T-shaped cover plate 63 is supported on the block 56 by screws 64 andmaintains the movable blade 61 in the groove in the block 56. Anoperating bar 65 is supported for sliding movement in the lower portionof the block 56 and is provided with a serpentine slot 66 therein (FIG.10). An operating pin 70 is threadably supported at its upper end in themovable blade 61 and its lower end is positioned in the slot 66 so thatinward and outward movement is imparted to the blade 61 with movement ofthe operating bar 65 through the support block 56. An elongate slot 71(FIG. 10) is provided in the support block 56 to permit movement of thepin 70, with movement of the blade 61.

The operating bar 65 is normally urged to the right in FIG. 9 anddownwardly in FIG. 10 by means of a tension spring 72, one end of whichis connected to the bar 65 and the other end of which is connected tothe housing of the drive shaft 55 (FIG. 9). As the operating bar 65 ismoved downwardly from the position shown in FIG. 10, the operating pin70 moves along the slot 66 to move the blade 61 outwardly. When the bar65 is moved upwardly to the position shown in FIG. 10, the pin 70 movesalong the slot 66 to thereby move the blade 61 to the outermostposition, as shown in FIG. 10.

During operation, the operating bar 65 is moved in timed relationship torotation of the circle of needles N by means of an operating arm 75having a downwardly depending cam portion 75a at its outer end. Theinner end of the arm 75 is fixed to the lower end of a sleeve 76 whichis supported for pivoting movement on the upper portion of an upstandingshaft 77. The inner end of a cam arm 80 is fixed on the upper end of thesleeve 76 and the outer free end is adapted'to engage a cam 81 fixed onthe drive shaft 55. A compression spring 82 surrounds the upper end ofthe shaft 77 and its upper end bears against an enlarged head 83 tonormally maintain the cam arm 80 in-horizontal alignment with the cam81.

' Pattern control means is provided for controlling the operation of themovable cutter blade 61. As shown in FIG. 9, this control means includesa lever 84 which is pivotally supported intermediate its ends on ahousing 85 surrounding the shaft 77. One end of the lever 84 extendsupwardly and into engagement with the lower surface of the operating arm75 while the opposite end is suitably connected to a Bowden wire 86. Theother end of the Bowden wire 86 extends to a suitable pattern drum onthe knitting machine, not shown, where it is connected .to a lever whichoperates from cams on the drum. The lever 84 is adapted to at timesraise the operating arm 75, sleeve 76, and cam arm 80 against thecompression spring 82 so that the cam arm 80 is raised above the levelof the cam 81. The spring 72 will then move the operating bar 65downwardly in FIG. so that the blade 61 is moved inwardly and maintainedin an inoperative position.

METHOD OF OPERATION The held loops of yarn are picked up at eachknitting station on the special transfer jacks T in the same manner asdescribed in connection with the embodiment shown in FIGS. 2-8. As theheld loops approach the cutter blade 61, the special transfer jacks Tare moved outwardly, so that the held loops are inclined outwardly at anangle. The cam 81 causes the blade 61 to be moved inwardly so that theoutwardly inclined loops are positioned in the cutting slot 62 in themovable blade 61. Any. loops being held on the regular transfer jacks Tare inclined inwardly, as shown in dotted lines in FIG. 11 so that theypass inside of the inner end of the cutter blade 61 and therefore arenot cut. The movement of the cam 81 is timed to move the cutter blade 61inwardly so that it is adjacent the circle of needles N as the heldloops approach the blade and the cutter blade 61 moves inwardly to severthe loops held on the transfer jacks T as the cam arm 80 moves off ofthe cam 81.

In each embodiment of the invention, it is necessary to move the specialtransfer jacks T outwardly at the point at which the held loops are tobe severed or cut when yarn loops are also being held on the regulartransfer jacks T, as during the knitting of an inturned welt. Theregular transfer jacks T are in an innermost position while the specialtransfer jacks T are moved outwardly to provide a separation of the heldloops which are to be cut and those held loops which are not to be cut.However, it is to be understood that it is not necessary to move theheld loops outwardly at the cutting point where a turned welt is notbeing formed and there are no loops being held on the regular transferjacks. While the invention has been described as utilizing a pair ofadjacent special transfer jacks T' operating above three inactiveneedles, it is to be understood that a single special transfer jack maybe used which operates over one'or more inactive needles to pick up andhold a loop of yarn to be cut in a subsequent step. Also, the fabricslitting apparatus of the present invention may beutilized in slitting amedial portion of the tubular fabric as well as adjacent either end.

In the drawings and specification there have been set forth preferredembodiments of the invention and although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation.

I claim:

1. In a circular knitting machine having a circle of rotating needles,at least one knitting station positioned closely adjacent the circle ofneedles and including yarn feeding means, and a dial bed positionedinside of said circle of needles and including a plurality of transferjacks supported for radial movement therein, the combination therewithof means for slitting seamless tubular fabric in a walewise direction asthe fabric is being knit, said slitting means comprising a. at least onespecial transfer jack supported in said dial bed and having a hookedouter end,

b. cam means positioned in advance of said knitting station andengageable with said special transfer jack for moving the hooked outerend beyond said circle of needles to pick up yarn at said knittingstation and to hold the yarn while it is knit on needles adjacentopposite sides thereof, and

c. yarn severing means positioned subsequent to said knitting stationand closely adjacent said circle of needles, said yarn severing meansbeing operable to engage and sever the yarn held by said transfer jack.

2. In a circular knitting machine according to claim 1 wherein said yarnsevering means is positioned outside of said circle of needles, andwherein said slitting means includes d. additional cam means engageablewith said special transfer jack for imparting outward movement theretoto move the yarn held thereby into engagement with said yarn severingmeans.

3. In a circular knitting machine according to claim 1 wherein said yarnsevering means (c) comprises a heater wire.

4. In a circular knitting machine according to claim 3 including a iatchring surrounding said circle of needles, and including means adjustablysupporting one end of said heater wire on said latch ring so that theposition of the other end of said heater wire may be adjusted, relativeto said circle of needles.

5. In a circular knitting machine according to claim 4 including anelectrical circuit connected to said heater wire, and a patterncontrolled switch in said electric circuit for directing electricalcurrent to said heater wire during the slitting of the fabric on theknitting machine.

6. In a circuar knitting machine according to claim 1 wherein said yarnsevering means (c) comprises a mechanical cutter operable to engage andsever the yarn held by said transfer jack.

7. In a circular knitting machine according to claim 6 including cammeans rotating in timed relationship to rotation of said circle ofneedles, and means engageable by said cam means for operating saidmechanical cutter at predetermined locations around said circle ofneedles.

8. In a circular knitting machine according to claim 6 including asinker cap surrounding said circle of needles, and wherein saidmechanical cutter is supported on said sinker cap and includes a bladeelement movable radially of said circle of needles.

9. A method of slitting a seamless tubular fabric in a walewisedirection as the fabric is being knit on a circular knitting machinehaving a rotating needle cylinder, 10

said transfer jack to form a held loop extending upwardly from saidneedles, and

c. severing the held loop of yarn at a location spaced from saidknitting station, and

d. repeating steps (a) and (b) during each of a plurality of needlecylinder rotations to slit the fabric as it is being knit.

10. A method according to claim 9 including the steps of projecting allof said transfer jacks outwardly and picking up yarn at said knittingstation, forming stitches on needles between said transfer jacks to forma held loop extending downwardly from each transfer jack, projectingselected transfer jacks outwardly to position the corresponding heldloops at an outwardly inclined angle from said needles, drawing theremaining transfer jacks inwardly to position the corresponding heldloops at an inwardly inclined angle from said needles, and severing theoutwardly inclined loops only at a location spaced from said knittingstation.

1. In a circular knitting machine having a circle of rotating needles, at least one knitting station positioned closely adjacent the circle of needles and including yarn feeding means, and a dial bed positioned inside of said circle of needles and including a plurality of transfer jacks supported for radial movement therein, the combination therewith of means for slitting seamless tubular fabric in a walewise direction as the fabric is being knit, said slitting means comprising a. at least one special transfer jack supported in said dial bed and having a hooked outer end, b. cam means positioned in advance of said knitting station and engageable with said special transfer jack for moving the hooked outer end beyond said circle of needles to pick up yarn at said knitting station and to hold the yarn while it is knit on needles adjacent opposite sides thereof, and c. yarn severing means positioned subsequent to said knitting station and closely adjacent said circle of needles, said yarn severing means being operable to engage and sever the yarn held by said transfer jack.
 2. In a circular knitting machine according to claim 1 wherein said yarn severing means is positioned outside of said circle of needles, and wherein said slitting means includes d. additional cam means engageable with said special transfer jack for imparting outward movement thereto to move the yarn held thereby into engagement with said yarn severing means.
 3. In a circular knitting machine according to claim 1 wherein said yarn severing means (c) comprises a heater wire.
 4. In a circular knitting machine according to claim 3 including a latch ring surrounding said circle of needles, and including means adjustably supporting one end of said heater wire on said latch ring so that the position of the other end of said heater wire may be adjusted, relative to said circle of needles.
 5. In a circular knitting machine according to claim 4 including an electrical circuit connected to said heater wire, and a pattern controlled switch in said electric circuit for directing electrical current to said heater wire during the slitting of the fabric on the knitting machine.
 6. In a circuar knitting machine according to claim 1 wherein said yarn severing means (c) comprises a mechanical cutter operable to engage and sever the yarn held by said transfer jack.
 7. In a circular knitting machine according to claim 6 including cam means rotating in timed relationship to rotation of said circle of needles, and means engageable by said cam means for operating said mechanical cutter at predetermined locations around said circle of needles.
 8. In a circular knitting machine according to claim 6 including a sinker cap surrounding said circle of needles, and wherein said mechanical cutter is supported on said sinker cap and includes a blade element movable radially of said circle of needles.
 9. A method of slitting a seamless tubular fabric in a walewise direction as the fabric is being knit on a circular knitting machine having a rotating needle cylinder, a circle of needles supported for vertical movement in said cylinder, a dial bed positioned inside of said circle of needles and including a plurality of transfer jacks, and at least one knitting station where yarn is fed to said needles and the needles are then drawn down to stitch forming level to form courses of stitch loops, said method comprising the steps of a. projecting at least one transfer jack outwardly and picking up a yarn at said knitting station, b. holding the yarn on said transfer jack while forming stitches on needles adjacent opposite sides of said transfer jack to form a held loop extending upwardly from said needles, and c. severing the held loop of yarn at a location spaced from said knitting station, and d. repeating steps (a) and (b) during each of a plurality of needle cylinder rotations to slit the fabric as it is being knit.
 10. A method according to claim 9 including the steps of projecting all of said transfer jacks outwardly and picking up yarn at said knitting station, forming stitches on needles between said transfer jacks to form a held loop extending downwardly from each transfer jack, projecting selected transfer jacks outwardly to position the corresponding held loops at an outwardly inclined angle from said needles, drawing the remaining transfer jacks inwardly to position the corresponding held loops at an inwardly inclined angle from said needles, and severing the outwardly inclined loops only at a location spaced from said knitting station. 